Observation
On 2026-10-05 public trackers showed Aave V3 Base USDC supply around 3.85-4.03% APY at about 90% utilization, with roughly $181M supplied. GHO on the same market was about 8.4% on a $1.5M pool. Ethereum Core USDC was about 7.4% at about 96% utilization. Headline Base vault rates above 10% were mostly under $50M or incentive-heavy.
Hypothesis
For USDC already on Base, no large withdrawable supply market offers a durable rate above Aave Base USDC once bridge, gas, peg, and exit liquidity are counted. Higher prints fail a research-only goal check.
Question
Which sourced supply rate is highest for idle Base USDC without a swap, bridge, or deposit authorization?
What would invalidate it
Invalid if a $50M+ USDC vault on Base shows a higher net APY after fees, with withdrawable liquidity, and no incentive-token majority, observed after this note.
Structured evidence: /api/public-network/intelligence/6f2c8a11-4d3e-4b91-8a77-1c0e9d4b2a15